Electrical contacts and method of manufacturing same



April 18, 1967 w. H. FLANAGAN 3,

ELECTRICAL CONTACTS AND METHOD OF MANUFACTURI G SAME Filed Oct. 19, 1965 2 Sheets-Sheet 1 FIG! SWEDGING OPERATION TO COMPLETE 26 CONTACT;

INVENTOR 58 FIG 4 WILLIAMHFLANAGAN g kTmi ATTO RN EY April 18, 1967 w. FLANAGAN 3,

ELECTRICAL CONTACTS AND METHOD OF MANUFACTURING SAME Filed Oct. 19, 1965 2 Sheets-Sheet 2 INVENTQR WILLIAM H. FLANAGAN ATTORNEY United States Patent 3,315,220 ELECTRICAL CONTACTS AND METHOD OF MANUFACTURING SAME William H. Flanagan, 394 Chestnut Hill Road, Stamford, Conn. 06903 Filed Oct. 19, 1965, Ser. No. 497,773 4 Claims. (Cl. 339-275) This invention relates generally to an electrical con nector and 'in particular to pin contacts and method of manufacturing pin contacts for use therein.

In the present day electrical industry there is a definite trend toward the miniaturization of electrical equipment and particularly in communications components. Specifically with reference to male plugs utilized in military aircraft communications systtems the components heretofore have been manufactured from square stock which is a procedure involving various machining operations principally screw machine in character. As this is a costly and time consuming process due to the small size of the end product, this invention which consists of a new and novel method of manufacturing pin contacts for male connectors has been developed.

Therefore, it is an object of this invention to provide a simple and improved method of manufacturing pin contacts for electrical connectors.

It is another object of this invention to provide a new and improved method of forming pin contacts from round stock by farging and swaging in a die.

It is another object of this invention to provide an improved method of forming pin contacts from standard round stock by die forming one end for retention within a housing and securing electrical wiring thereto.

Other objects of this invention will in part, be obvious and will in part appear hereinafter.

In the drawings:

FIG. 1 is a view in front elevation of round stock with the end machine.

FIG. 2 is a view in section of the machined round stock within a die after the swedging operation.

FIG. 3 is a view in front elevation of the completed pin contact.

FIG. 4 is a bottom plan view of the completed pin contact.

FIG. 5 is a view in perspective of the male connector with the pin contacts having the wiring secured thereto with the lower housing in position for assembly.

FIG. 6 is a view in perspective of the completed connector with the upper and lower housings snapped into position within the casing.

Broadly stated the feature of this invention is to provide a new and improved method of manufacturing pin contacts for use with electrical connectors which eliminate extensive machining operations of that portion of the contact which is positioned within a housing. Pin contacts by their very nature are designed to fit within split molded housings having recesses formed therein to permit axial withdrawal of the pin contact. By utilizing a forging operation to form a portion of the pin contact having a configuration adapted to conform to a pro-molded housing and having vertical tab members adapted to secure electrical leads therebetween machining and drilling operations are eliminated.

To the accomplishment of this end the foregoing related ends, the present invention then consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain means in the carrying out of the invention, such disclosed means illustrating however, but one of the various ways in which the principle in the invention may be employed.

Referring to the drawings there is shown in FIG. 1 a portion of round stock 10 having an elongated tail portion 12. The primary operation in the manufacture of the pin contact consists of forming a ball 14 at one end 16 of the stock 10 and cutting a groove 18 adjacent thereto with vertical walls 20 on the tail portion 12 and a chamfered wall 22 on the ball 14.

The second operation consists of transferring the portion 10 as shown in FIG. 1 to a die 24 having a split tubular aperture 26 adapted to receive and retain a predetermined portion of the tail portion 12. It will be seen by referring to FIG. 2 that the die has two steps 28 and 30 so that the initial positioning of the stock 10 within the aperture 26 allows a portion of the tail portion 12 to be elevated above the step 30. The punch 34 having the desired configuration (not shown) by its downward movement forces the tail portion 12 downward onto the step 30 and forms the tail portion 12 into the shape as shown in FIG. 3. The shape of the tail portion 12 consists of two level areas 38 and 40 with abutments 42 and 44 adapted to ride in corresponding slots 46 and 48 of the housing 50 to prevent forward movement of the pin contact after assembly within the hosuing 50. Two upwardly extending tab members 52 and 54 are formed so as to be laterally spaced from each other a distance sufiicient to accommodate and receive the bare end of a lead 56 so that they may be crimped together or act as a solder well to retain the lead in electrical contact with the contact as shown in FIG. 4. The bottom surface 58 of the tail portion 12 of the contact is within one plane to provide a fiat continuous surface for engagement with the inner surface 64 of the housing 50.

Further steps to complete the manufacture of the contact consist of hardening and plating the pin contact to increase its electrical conductivity.

FIGURES 5 and 6 illustrate the positioning of the contact with the power lead 62 which extends through the casing 64. As shown in FIG. 5 the electrical leads 56 are secured between the tab members 52 and 54 and the strain relief cords 66 and 68 extend through the housing 50. When the lower casing 50 and a similar upper casing (not shown) are positioned on the upper and lower surface of the contacts, the assembly is slid into telescopic engagement with the casing 64 as shown in FIG. 6 and the strain relief cards passed around the outer surface of the housings within grooves 72 and securely tied together.

While there have been described herein What are at present considered preferred embodiments of the invention it will be obvious to those skilled in the art that modifications and changes may be made therein without departing from the essence of the invention. It is therefore to be understood that the exemplary embodiments are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims, and that all modifications that come within the meaning and range of equivalency of the claims are intended to be included herein.

I claim:

1. A method of manufacturing an electrical contact comprising the steps of:

forming a lead on one end of a solid piece of round metal stock, inserting said lead end into a tubular apertured die, with a tail portion positioned between a flat surface of said die and a punch, said punch having a predetermined facial configuration, compressing said tail portion within said die to define a pair of flattened surfaces having a width greater than said metal stock and a thickness less than said metal stock and forwardly facing abutments on said flattened surfaces and simultaneously therewith forging a pair of vertically extending laterally spaced tab members disposed intermediate said fiat surfaces.

27 A method of manufacturing an electrical contact as set forth in claim 1, where a circular groove is cut in said metal stock at a point spaced from the lead end, the walls of said groove adjacent the lead end having a chamfered edge portion with the walls of the groove abutting the tail portion being normal to the plane thereof,

3. An electrical pin contact comprising an elongated solid tubular portion having a lead in portion at one end thereof, the other end of said contact having a fiat surface with a Width greater than and a thickness less than said tubular portion with forwardly facing abutments to prevent forward movementof the pin contact after assembly within a housing, a pair of imperforate tab members adjacent said fiat surface extending normal thereto and laterally spaced from each other to accommodate and receive a bare end of an electrical conductor and a second flat surface disposed between said tab members and the elongated tubular portion. 1

4. An electrical pin contact comprising an elongated solid tubular portion having a lead in portion at one end thereof, a circular groove disposed at a point spaced from said one end, the other end of said contact having a flat surface with a width greater than and a thickness less than said tubular portion, with forwardly facing abutments to prevent forward movement of the pin contact after assembly within a housing, a pair of imperforate tab members adjacent said fiat surface extending normal thereto and laterally spaced from each other to accommodate and receive a bare end of an electrical conductor and a second fiat surface disposed between said tab members and the elongated tubular portion.

References Cited by the Examiner UNITED STATES PATENTS 2,451,800 10/ 1948 Buchanan et a1 339-223 2,476,738 7/1949 Klumpp 339-276 X 2,861,324 11/1958 Klnmpp 339-218 X 3,157,454 1l/1964 Collins 339-276 X FOREIGN PATENTS 489,345 1/1954 Italy.

74,258 11/ 1948 Norway.

MARVIN A. CHAMPION, Primary Examiner.

P. TEITELBAUM, Assistant Examiner. 

3. AN ELECTRICAL PIN CONTACT COMPRISING AN ELONGATED SOLID TUBULAR PORTION HAVING A LEAD IN PORTION AT ONE END THEREOF, THE OTHER END OF SAID CONTACT HAVING A FLAT SURFACE WITH A WIDTH GREATER THAN AND A THICKNESS LESS THAN SAID TUBULAR PORTION WITH FORWARDLY FACING ABUTMENTS TO PREVENT FORWARD MOVEMENT OF THE PIN CONTACT AFTER ASSEMBLY WITHIN A HOUSING, A PAIR OF IMPERFORATE TAB MEMBERS ADJACENT SAID FLAT SURFACE EXTENDING NOMRAL THERETO AND LATERALLY SPACED FROM EACH OTHER TO ACCOM- 